/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
 
package org.epic.perleditor.preferences;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;

/**
 * An overlaying preference store.
 */
public class OverlayPreferenceStore  implements IPreferenceStore {
    
    
    public static final class TypeDescriptor {
        private TypeDescriptor() {
        }
    }
    
    public static final TypeDescriptor BOOLEAN= new TypeDescriptor();
    public static final TypeDescriptor DOUBLE= new TypeDescriptor();
    public static final TypeDescriptor FLOAT= new TypeDescriptor();
    public static final TypeDescriptor INT= new TypeDescriptor();
    public static final TypeDescriptor LONG= new TypeDescriptor();
    public static final TypeDescriptor STRING= new TypeDescriptor();
    
    public static class OverlayKey {
        
        TypeDescriptor fDescriptor;
        String fKey;
        
        public OverlayKey(TypeDescriptor descriptor, String key) {
            fDescriptor= descriptor;
            fKey= key;
        }
    }
    
    private class PropertyListener implements IPropertyChangeListener {
                
        /*
         * @see IPropertyChangeListener#propertyChange(PropertyChangeEvent)
         */
        public void propertyChange(PropertyChangeEvent event) {
            OverlayKey key= findOverlayKey(event.getProperty());
            if (key != null)
                propagateProperty(fParent, key, fStore); 
        }
    }
    
    
    private IPreferenceStore fParent;
    private IPreferenceStore fStore;
    private OverlayKey[] fOverlayKeys;
    
    private PropertyListener fPropertyListener;
    
    
    public OverlayPreferenceStore(IPreferenceStore parent, OverlayKey[] overlayKeys) {
        fParent= parent;
        fOverlayKeys= overlayKeys;
        fStore= new PreferenceStore();
    }
    
    private OverlayKey findOverlayKey(String key) {
        for (int i= 0; i < fOverlayKeys.length; i++) {
            if (fOverlayKeys[i].fKey.equals(key))
                return fOverlayKeys[i];
        }
        return null;
    }
    
    private boolean covers(String key) {
        return (findOverlayKey(key) != null);
    }
    
    private void propagateProperty(IPreferenceStore orgin, OverlayKey key, IPreferenceStore target) {
        
        if (orgin.isDefault(key.fKey)) {
            if (!target.isDefault(key.fKey))
                target.setToDefault(key.fKey);
            return;
        }
        
        TypeDescriptor d= key.fDescriptor;
        if (BOOLEAN == d) {
            
            boolean originValue= orgin.getBoolean(key.fKey);
            boolean targetValue= target.getBoolean(key.fKey);
            if (targetValue != originValue)
                target.setValue(key.fKey, originValue);
                
        } else if (DOUBLE == d) {
            
            double originValue= orgin.getDouble(key.fKey);
            double targetValue= target.getDouble(key.fKey);
            if (targetValue != originValue)
                target.setValue(key.fKey, originValue);
        
        } else if (FLOAT == d) {
            
            float originValue= orgin.getFloat(key.fKey);
            float targetValue= target.getFloat(key.fKey);
            if (targetValue != originValue)
                target.setValue(key.fKey, originValue);
                
        } else if (INT == d) {

            int originValue= orgin.getInt(key.fKey);
            int targetValue= target.getInt(key.fKey);
            if (targetValue != originValue)
                target.setValue(key.fKey, originValue);

        } else if (LONG == d) {

            long originValue= orgin.getLong(key.fKey);
            long targetValue= target.getLong(key.fKey);
            if (targetValue != originValue)
                target.setValue(key.fKey, originValue);

        } else if (STRING == d) {

            String originValue= orgin.getString(key.fKey);
            String targetValue= target.getString(key.fKey);
            if (targetValue != null && originValue != null && !targetValue.equals(originValue))
                target.setValue(key.fKey, originValue);

        }
    }
    
    public void propagate() {
        for (int i= 0; i < fOverlayKeys.length; i++)
            propagateProperty(fStore, fOverlayKeys[i], fParent);
    }
    
    private void loadProperty(IPreferenceStore orgin, OverlayKey key, IPreferenceStore target, boolean forceInitialization) {
        TypeDescriptor d= key.fDescriptor;
        if (BOOLEAN == d) {
            
            if (forceInitialization)
                target.setValue(key.fKey, true);
            target.setValue(key.fKey, orgin.getBoolean(key.fKey));
            target.setDefault(key.fKey, orgin.getDefaultBoolean(key.fKey));
            
        } else if (DOUBLE == d) {
            
            if (forceInitialization)
                target.setValue(key.fKey, 1.0D);
            target.setValue(key.fKey, orgin.getDouble(key.fKey));
            target.setDefault(key.fKey, orgin.getDefaultDouble(key.fKey));
            
        } else if (FLOAT == d) {
            
            if (forceInitialization)
                target.setValue(key.fKey, 1.0F);
            target.setValue(key.fKey, orgin.getFloat(key.fKey));
            target.setDefault(key.fKey, orgin.getDefaultFloat(key.fKey));
            
        } else if (INT == d) {
            
            if (forceInitialization)
                target.setValue(key.fKey, 1);
            target.setValue(key.fKey, orgin.getInt(key.fKey));
            target.setDefault(key.fKey, orgin.getDefaultInt(key.fKey));
            
        } else if (LONG == d) {
            
            if (forceInitialization)
                target.setValue(key.fKey, 1L);
            target.setValue(key.fKey, orgin.getLong(key.fKey));
            target.setDefault(key.fKey, orgin.getDefaultLong(key.fKey));
            
        } else if (STRING == d) {
            
            if (forceInitialization)
                target.setValue(key.fKey, "1"); //$NON-NLS-1$
            target.setValue(key.fKey, orgin.getString(key.fKey));
            target.setDefault(key.fKey, orgin.getDefaultString(key.fKey));
            
        }
    }
    
    public void load() {
        for (int i= 0; i < fOverlayKeys.length; i++)
            loadProperty(fParent, fOverlayKeys[i], fStore, true);
    }
    
    public void loadDefaults() {
        for (int i= 0; i < fOverlayKeys.length; i++)
            setToDefault(fOverlayKeys[i].fKey);
    }
    
    public void start() {
        if (fPropertyListener == null) {
            fPropertyListener= new PropertyListener();
            fParent.addPropertyChangeListener(fPropertyListener);
        }
    }
    
    public void stop() {
        if (fPropertyListener != null)  {
            fParent.removePropertyChangeListener(fPropertyListener);
            fPropertyListener= null;
        }
    }
    
    /*
     * @see IPreferenceStore#addPropertyChangeListener(IPropertyChangeListener)
     */
    public void addPropertyChangeListener(IPropertyChangeListener listener) {
        fStore.addPropertyChangeListener(listener);
    }
    
    /*
     * @see IPreferenceStore#removePropertyChangeListener(IPropertyChangeListener)
     */
    public void removePropertyChangeListener(IPropertyChangeListener listener) {
        fStore.removePropertyChangeListener(listener);
    }
    
    /*
     * @see IPreferenceStore#firePropertyChangeEvent(String, Object, Object)
     */
    public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) {
        fStore.firePropertyChangeEvent(name, oldValue, newValue);
    }

    /*
     * @see IPreferenceStore#contains(String)
     */
    public boolean contains(String name) {
        return fStore.contains(name);
    }
    
    /*
     * @see IPreferenceStore#getBoolean(String)
     */
    public boolean getBoolean(String name) {
        return fStore.getBoolean(name);
    }

    /*
     * @see IPreferenceStore#getDefaultBoolean(String)
     */
    public boolean getDefaultBoolean(String name) {
        return fStore.getDefaultBoolean(name);
    }

    /*
     * @see IPreferenceStore#getDefaultDouble(String)
     */
    public double getDefaultDouble(String name) {
        return fStore.getDefaultDouble(name);
    }

    /*
     * @see IPreferenceStore#getDefaultFloat(String)
     */
    public float getDefaultFloat(String name) {
        return fStore.getDefaultFloat(name);
    }

    /*
     * @see IPreferenceStore#getDefaultInt(String)
     */
    public int getDefaultInt(String name) {
        return fStore.getDefaultInt(name);
    }

    /*
     * @see IPreferenceStore#getDefaultLong(String)
     */
    public long getDefaultLong(String name) {
        return fStore.getDefaultLong(name);
    }

    /*
     * @see IPreferenceStore#getDefaultString(String)
     */
    public String getDefaultString(String name) {
        return fStore.getDefaultString(name);
    }

    /*
     * @see IPreferenceStore#getDouble(String)
     */
    public double getDouble(String name) {
        return fStore.getDouble(name);
    }

    /*
     * @see IPreferenceStore#getFloat(String)
     */
    public float getFloat(String name) {
        return fStore.getFloat(name);
    }

    /*
     * @see IPreferenceStore#getInt(String)
     */
    public int getInt(String name) {
        return fStore.getInt(name);
    }

    /*
     * @see IPreferenceStore#getLong(String)
     */
    public long getLong(String name) {
        return fStore.getLong(name);
    }

    /*
     * @see IPreferenceStore#getString(String)
     */
    public String getString(String name) {
        return fStore.getString(name);
    }

    /*
     * @see IPreferenceStore#isDefault(String)
     */
    public boolean isDefault(String name) {
        return fStore.isDefault(name);
    }

    /*
     * @see IPreferenceStore#needsSaving()
     */
    public boolean needsSaving() {
        return fStore.needsSaving();
    }

    /*
     * @see IPreferenceStore#putValue(String, String)
     */
    public void putValue(String name, String value) {
        if (covers(name))
            fStore.putValue(name, value);
    }

    /*
     * @see IPreferenceStore#setDefault(String, double)
     */
    public void setDefault(String name, double value) {
        if (covers(name))
            fStore.setDefault(name, value);
    }

    /*
     * @see IPreferenceStore#setDefault(String, float)
     */
    public void setDefault(String name, float value) {
        if (covers(name))
            fStore.setDefault(name, value);
    }

    /*
     * @see IPreferenceStore#setDefault(String, int)
     */
    public void setDefault(String name, int value) {
        if (covers(name))
            fStore.setDefault(name, value);
    }

    /*
     * @see IPreferenceStore#setDefault(String, long)
     */
    public void setDefault(String name, long value) {
        if (covers(name))
            fStore.setDefault(name, value);
    }

    /*
     * @see IPreferenceStore#setDefault(String, String)
     */
    public void setDefault(String name, String value) {
        if (covers(name))
            fStore.setDefault(name, value);
    }

    /*
     * @see IPreferenceStore#setDefault(String, boolean)
     */
    public void setDefault(String name, boolean value) {
        if (covers(name))
            fStore.setDefault(name, value);
    }

    /*
     * @see IPreferenceStore#setToDefault(String)
     */
    public void setToDefault(String name) {
        fStore.setToDefault(name);
    }

    /*
     * @see IPreferenceStore#setValue(String, double)
     */
    public void setValue(String name, double value) {
        if (covers(name))
            fStore.setValue(name, value);
    }

    /*
     * @see IPreferenceStore#setValue(String, float)
     */
    public void setValue(String name, float value) {
        if (covers(name))
            fStore.setValue(name, value);
    }

    /*
     * @see IPreferenceStore#setValue(String, int)
     */
    public void setValue(String name, int value) {
        if (covers(name))
            fStore.setValue(name, value);
    }

    /*
     * @see IPreferenceStore#setValue(String, long)
     */
    public void setValue(String name, long value) {
        if (covers(name))
            fStore.setValue(name, value);
    }

    /*
     * @see IPreferenceStore#setValue(String, String)
     */
    public void setValue(String name, String value) {
        if (covers(name))
            fStore.setValue(name, value);
    }

    /*
     * @see IPreferenceStore#setValue(String, boolean)
     */
    public void setValue(String name, boolean value) {
        if (covers(name))
            fStore.setValue(name, value);
    }
}
